Mannheim



I philosophy,-a citizen of the Swiss Republic, re-,

factors of Blue Alizarin Dye,

1 RENEBonn,forinANNHErM, ASSIGNOR To T its nltnlson'n' ANILIN" Ann;

SODAYFA'BRIIQJQE L nwIssHAFnN.o -rtinnnmn RMANY;

-' BLlJE-ALI ZA 'R IIN evi -z.

SPECIFICATION a min pm of Letters Patent Ne. 519,229, dated mil, 1e94, 1

To aldwhomit may cancer-1g Be 1t known that I, RENE, BOHN, doctor of siding at Mannheirm i'n the 'Grand Duchy of Baden and Empire of Germany, have invented new and useful Improvements in the Manu- (for which I have received Letters Patent in In the United States Letters Patent Nos.

- 401,634, and

401,635, granted to me, I have described various blue to green alizarin dyes furic acid in a each case, upon certaindye-stuffs of the aliz-- tors Patent co'nstit arin series. The dyes patented in these Leta ute very valuable articles 0!. commerce 4 a In the specification toLetters Patent No. 502,6031 have described the production of alizarin dye giving blue shades on chromed wool, by the successive treatment of dinitroanthraquinone (preferably 1.4: dinitro anthraquinone) first with fuming and then with ordinary sulfuric acid.

The present invention relates to a specific dye whichis included g'enericallyin the Letters Patent aforesaid and which possesses the generic properties therein set forthwhile differing in several respects from the specific dye obtained by proceeding in the manner described in the example. Thus for instance itbyields a redder shade of color on chromed fi er.

The 1.4 dinitro-anthraquinone is comparatively insoluble in nearly all the usual solve ents consequently in its manufacture the mother liquors contain little or none of this body but other more soluble nitro -bodies which can be regained as a by-product. Now according to my present invention 1 subject this by-product to successive treatment first with turning and then with ordinary concentrated sulfuric acid in the manner hereinaiter described. The said "by-product consists in the main of alpha-.dinitro-anthraqui- I a I England, Nos. 19,58? and 19,589, dated November,,12-,,l891,

and in Germany, No. 'Z2,685, dated June 5,,

11892) of which the following is a specification.

. 19,6 89, and in Germany June 5,1892 ,No. 72,685.

" none and delta dinitro-anthraqninone; fur- Application filed December 27,1893. sesame. 494.884. lemmas.) Patented in England November 12', 1891,][09- IQBBBend.

ther otherindefinite practically immaterial in a this process (see German Patent'No. 72,685)

tro-anth raquinones from one another and use nitro-productswhich are. a

1 V 1 It is'of course possible toseparate the alpha and delta dinino practical advantage is thereby gained This by-product can also be prepared by ex-. tracting a crude dinitro-anthraquinone with acetone. I have foundthat the best resultcan not readily be obtained when treating thisjmixed dinitro-anthraquinone (or the isolated components) with fuming sulfuric acid containing about twelve per cent. of free an- .hydride (S0,) inthe first step according to the process described, as applied to. the 1.4 dinitro-anthraquinone, in the aforesaid specification No. 502,603; but that it is better to use a stronger acid ashereinafter set forth.

The following example will serve to illusbest be carried into-practice efiect and my new dye obtained. By parts mean parts by-v weight.

Example: Mix about ten (10) parts of the 10- trate the manner in which the invention can dinitro-anthraquinone mixture above defined (or of the isolated alpha or beta dinitro-anthraquinone) andoneto'two (1 to 2) parts sulfurwith about one hundred (100) parts of fuming sulfuric acid containing .about forty per cent. of free anhydride (4 0% S0 heat the mixture to a temperature of about one hundred and thirty degrees centigrade, (130c.)

and maintain the heat for about one and a half to two hours, (it to 2 hrs.) Anew intermediate coloring matt-er readily soluble Win water is produced. Allow the melt to cooland when cold pour it into water, and by means of common salt precipitate the intermediate product, filter, press and dry. Next mix aboutone (1) part of the dryintermediate product so obtained with about 'ten (10) parts of ordinary concentrated sulfuric acid containing about ninety-five per cent. of real acid (95% 11 80,). IIeat themixture to about one hundred and thirty degrees centigrade, (130 0.) for about live (5) hours or until the resulting dye is practically insoluble in wav ter. Then pour the whole into water, filter,

' wash with warm water, press and dry or presortie for use in the form of paste.

In the above example instead of isolating 5 the intermediate coloring matter from the melt and treating the isolated body with concentrated sulfuric acid, a similar dye can be obtainedby adding the concentrated acid to the melt and further heating this mixture 19 till the desired almost insoluble dye is obtained. Further the strength of acid used, the temperature and the proportions described in the above example may be varied V Without departing from the naturcof the invention.

' My new dyestuff is characterized by the following propertiesz-1t occurs in commerce in the form of paste or as a dry dark colored powder, it is practically insoluble on stirring 20 with cold water, but on boiling it yields a dull claret red solutionwhich turns blue violet on boiling with alum solution, it is soluble in alcohol giving a magenta-red slightlyfluorescent solution, it is almost insoluble in a 5' ether and practically insoluble in cold benzone but gives a magenta-red solution on boiling; it givesaviolet-blue solution in sulfuric acid, a magenta-red solution in amino and in glacial acetic acid.

Now what I claim is The new blue alizarin dye hereinbefore described which can be derived by the successive treatment of the dinitro-anthraquinones hereinbefore defined first with fuming and afterward with concentrated sulfuric acid which, when dry, appears in the form of a darl colored powder, soluble in alcohol, almost 1- soluble in ether and cold benzene, practical insoluble in cold water, more soluble on be ing, giving a dull claret red solution wh ch changes in color to blue violet on boiling with alum solution, soluble in concentrated sul: furic'acid giving a violet blue solution all sub: stantially as described.

"In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses. g f Runs Bonn;

Witnesses: ERNEST F. EH HA-a'ng, ADOPH REUTLINGER. 

